package cn.tedu.sp06.fb;

import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

@Slf4j
@Component
public class OrderFB implements FallbackProvider {
    /*
    设置调用哪个后台服务，会应用当前降级类
    - "item-service"  只针对商品降级
    - "*"  对所有服务都降级
    - null 对所有服务都降级
     */
    @Override
    public String getRoute() {
        return "order-service";
    }
    // 发回给客户端的降级响应数据
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
                //用来关闭下面方法中的流
                //BASIS 流内存数组的流,不占用底层系统资源,不需要
            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult - {code:500,msg:调用商品失败,data:null}
                String json = JsonResult.err().code(500).msg("调用订单失败").toString();
                return new ByteArrayInputStream(json.getBytes(StandardCharsets.UTF_8));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
